The loading and off-loading of petroleum products into the compartments of transport trucks, and from such compartments into storage tanks are common procedures well-known in the art. The separate compartments of a typical tank truck will often contain different fuels such as various grades of gasoline, diesel, fuel oils and kerosene. When loading these compartments with fuel, visual inspection is typically not possible and thus overfill sensors are installed in the respective tanks to provide signal feedback to shut down the delivery pumps when loading is complete. An example of such a delivery system is, for example, set forth in United States Patent Application Publication 2005/0139286 where a modular multi-port manifold and fuel delivery system is disclosed having a plurality of ports in fluid communication with corresponding compartments of the fuel delivery vehicle.
There are, however, limitations in such fuel delivery systems as they may be readily compromised and thus operate in less than an optimal manner. Since the tanks of transport trucks usually cannot be visually inspected while filling, overfill sensors are utilized to provide signal feedback to shut down the loading pumps when the appropriate level is reached. These typically comprise a probe that extends downwardly from the top of the tank compartment and, if properly operational, will sense the presence of the fuel when it rises to a sensor on the bottom end of the probe. However if the probe is non-functional for any reason, such as mishandling by operating personnel or component failure, or if the length of the probe tube that carries a sensor that detects the presence of the fuel is not properly matched to the compartment in which it is installed, the compartment may be either underloaded or overfilled. This can occur, for example, when a defective probe is replaced after a repair and a probe of improper length is installed. Also, improper signal wiring during installation of a system also adds to poor reliability, resulting in frustrated end users.
An overfill detection probe in common use comprises an optical detector and an electronic circuit board which communicates with the detector and also interfaces with other electronics of the system. However, the detector projects from the bottom end of the probe and is thus exposed to damage and malfunction if not carefully handled and installed. Also, the circuit board and associated wiring connections in the probe may be damaged due to mishandling and render the probe inoperable. Any such failure of an electrical element of the system may require the end user to recertify system integrity.